net: ieee802154: fix nl802154 add llsec key

This patch fixes a nullpointer dereference if NL802154_ATTR_SEC_KEY is
not set by the user. If this is the case nl802154 will return -EINVAL.

Reported-by: syzbot+ce4e062c2d51977ddc50@syzkaller.appspotmail.com
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210221174321.14210-3-aahringo@redhat.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 460e538..4aa9000 100644 (file)
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1544,7 +1544,8 @@ static int nl802154_add_llsec_key(struct sk_buff *skb, struct genl_info *info)
        struct ieee802154_llsec_key_id id = { };
        u32 commands[NL802154_CMD_FRAME_NR_IDS / 32] = { };
 
-       if (nla_parse_nested_deprecated(attrs, NL802154_KEY_ATTR_MAX, info->attrs[NL802154_ATTR_SEC_KEY], nl802154_key_policy, info->extack))
+       if (!info->attrs[NL802154_ATTR_SEC_KEY] ||
+           nla_parse_nested_deprecated(attrs, NL802154_KEY_ATTR_MAX, info->attrs[NL802154_ATTR_SEC_KEY], nl802154_key_policy, info->extack))
                return -EINVAL;
 
        if (!attrs[NL802154_KEY_ATTR_USAGE_FRAMES] ||